1. Field of the Invention
The present invention relates to a display device and a manufacturing method thereof.
2. Discussion of the Background
Recently, flat panel displays that are small and light weight have attracted attention. Examples of a flat panel display include a liquid crystal display (LCD), an organic light emitting display (OLED), and an electrophoretic display device. A flat panel display may include a thin film transistor substrate having a thin film transistor. The thin film transistor may be connected to a pixel electrode.
The thin film transistor includes a drain electrode and a source electrode with a channel region therebetween. The drain electrode is connected to the pixel electrode and drives the pixel electrode by charge transfer in the channel region. In order to improve the display quality, a current should not flow when the thin film transistor is turned off. However, the charge transfer outside the channel region may cause a leakage current, which may deteriorate the off-characteristics of the thin film transistor.
Particularly, the leakage current may become a problem in a thin film transistor that uses an organic semiconductor. The organic semiconductor may be formed by an inkjet method that does not require additional patterning and, if the organic semiconductor layer is disposed over a wide area outside the channel region rather than limited to the channel region, a current leakage may be generated.
Meanwhile, in order to limit the organic semiconductor layer to be formed within a certain region, a barrier rib may be used. However, since the barrier rib is separately formed, the process may be complicated. In addition, even if the barrier rib is formed, it may be difficult to limit the formation the organic semiconductor layer to the channel region, thus still resulting in a current leakage.